The long range goal of this lab is to determine the actors that produce the motoric characteristics of the mentally retarded individual, especially the Down syndrome (DS) individual. These characteristics are usually described as 'slowness' and 'clumsiness'. While often considered to be abnormalities they are vaguely defined in motor control theories. The mentally retarded and Down syndrome (DS) individual are also known to have a different polarity and morphology of cortical movement-related potentials (MRP). We have argued from the existing information that these behavioral and MRP characteristics may be better understood as different stages in adaptive developmental processes. Consequently, they are amenable to training and may not be specific to DS or mentally retarded individuals. Three studies have been designed to confirm the developmental nature and lack of specificity of these characteristics of motor performance and MRP. The studies investigate the relationship between movement proficiency and neural activity as manifested in the MRP. One study will give extensive practice to DS and non-DS individuals on a single-joint movement within the individuals behavioral repertoire. This will allow determination of training on the MRP as skillful execution is developed. The comparison of individuals with mental retardation but not DS, individuals with DS who are not mentally retarded, and DS mentally retarded adults with individuals neither mentally retarded nor DS will allow determination of the specificity to DS and mental retardation. A second study will ask non-retarded adults to learn a novel movement they are unable to perform. This will allow the characteristics of the brain's MRP during the initial acquisition of a movement to be determined. A third study will use biofeedback of the MRP so that DS and non-DS individuals can learn to maximize this cortical manifestation of movement preparation during a single-joint movement. It can then be determined if changes in this cortical sign of motor preparation facilitates performance of the movement. The information obtained will contribute to the conceptualization of training interventions as well as recreational possibilities of the DS and retarded individual.